Filing devices for storage of files or other items are well known and of many different types. Such filing devices include bins, binders, pockets, frames and generally any type of container or binder for storing paper files, magnetic media or other items.
One type of filing device has a hook for supporting it from a hanger bar. Such devices include "end hook devices", which have a hook at one end and "center hook devices" which have a hook between the ends of the device, although not necessarily in the center. An example of an end hook device is the bin shown in FIG. 1 and an example of a center hook device is the cartridge binder shown in FIG. 1.
Previously, end hook devices required one type of hanger bar and center hook devices required a different, separate hanger bar. Existing cartridge binders as shown in FIGS. 1 and 2 have a shoulder at each end so that the binder can alternatively be used in a conventional hanging type filing system, where the file is suspended from each end by rails. In either method of filing the cartridge binder, to access the inner pages of the document bound by the cartridge, the binder had to be removed from the hanger bar or the rails and supported manually or a surface found to lay the document down on so that it could be opened. Although inconvenient, this has long been a conventional way of accessing cartridge bound documents.